THE Department of Planning and Environment has recommended that the Hunter Valley Operations South mine near Singleton be allowed to lift its production from 16 million tonnes a year to 20 million tonnes, describing it as “a relatively minor expansion”.
It has also recommended the mine be allowed to have a larger final void, while recognising that the “hypersaline” water left behind would be “unusable”.
In recommending the changes be approved, the department says the mine would extract an extra 56.8 million tonnes of coal, resulting in an extra $243 million in royalties and $160 million in taxes.
There would be no impact on workforce numbers, which total about 1500 across the North and South pits.
The changes would allow the mine to reach deeper coal, but this would also result in a final landform in places 80 metres higher than was currently approved.
The department received 45 submissions on the proposal, of which 32 were objections.
A number of objectors, including Camberwell resident Deidre Olufsson, pointed to the substantial “final void” that would be left at the mine once production was finished.
The department says the proposed changes would take the surface area of the final void to 523 hectares, compared with the 404 hectares approved in 2008.
It would take about 250 years after the end of mining for the void to reach “equilibrium” at a salinity of 12,800mg of salt per litre. By comparison, brackish estuary water contains 500mg/litre to 5000mg/litre, while ocean water is about 19,400 mg/litre
“This hypersaline water would not be released into the surrounding environment; however, it would ultimately be unusable,” the department says.
Ms Olufsson said final voids had been outlawed in American coalmining since 1977 with the Surface Mining Control Reclamation Act, and the same thing should happen here.
The department said it recognised public concern at “the mere presence” of a final void but said Coal & Allied had “prior approval” to use one in its final landform.
“In the absence of a NSW government policy on final voids”, the proposed design aligned with the department’s “current objectives” in that it was “minimised in size to the greatest extent possible”.
The recommended approval for the mine extension has been sent to the Planning Assessment Commission for a decision.